One equation eddy

Rickard.Solsjo · July 12, 2010, 16:33

If I change the turbulenceproperties from RAS to LES the one equation eddy model (sth like that) is solved.
I tried looking at the code but can someone tell me in words how it works ?

Thx

waynezw0618 · July 13, 2010, 23:03

there are two examples in pisoFoam

NorbertB · July 14, 2010, 04:52

Hi Rickard,

Even if I cannot explain you exactly this model, you could find some help in the following threads :

# First thread (4 pages, must see)
# Second thread, shorter but still relevant
# Eugene's thesis

Hope it helps

Rickard.Solsjo · July 14, 2010, 05:28

I mean of course how the one equation eddy is solved, not how it is implemented

maysmech · March 31, 2011, 16:36

Quote:

Originally Posted by Rickard.Solsjo

I mean of course how the one equation eddy is solved, not how it is implemented

I have same question.

Rickard.Solsjo · April 1, 2011, 02:20

Norbert is right, just read Eugene's thesis.
Basically, the subgrid scale (eddy) viscosity comes into some of the terms in the governing equation. To solve this, the eddy viscosity is modeled similarly as in the smagorinsky case but with a subgrid scale turbulent kinetic energy which is solved with another transport equation.
Something like
nu(sgs)=C(nu)sqrt(K(sgs))*filterwidth.
Just look at eugenes thesis

July 12, 2010, 16:33	One equation eddy	#1
Rickard.Solsjo Senior Member Rickard Join Date: May 2010 Location: Lund, Skåne, Sweden Posts: 143 Rep Power: 15	If I change the turbulenceproperties from RAS to LES the one equation eddy model (sth like that) is solved. I tried looking at the code but can someone tell me in words how it works ? Thx

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July 13, 2010, 23:03		#2
waynezw0618 Senior Member wayne.zhang Join Date: Mar 2009 Location: Shanghai, Shanghai, P.R.China Posts: 309 Rep Power: 18	there are two examples in pisoFoam

July 14, 2010, 04:52		#3
NorbertB New Member Join Date: Jun 2010 Posts: 23 Rep Power: 15	Hi Rickard, Even if I cannot explain you exactly this model, you could find some help in the following threads : # First thread (4 pages, must see) # Second thread, shorter but still relevant # Eugene's thesis Hope it helps

July 14, 2010, 05:28		#4
Rickard.Solsjo Senior Member Rickard Join Date: May 2010 Location: Lund, Skåne, Sweden Posts: 143 Rep Power: 15	I mean of course how the one equation eddy is solved, not how it is implemented

April 1, 2011, 02:20		#6
Rickard.Solsjo Senior Member Rickard Join Date: May 2010 Location: Lund, Skåne, Sweden Posts: 143 Rep Power: 15	Norbert is right, just read Eugene's thesis. Basically, the subgrid scale (eddy) viscosity comes into some of the terms in the governing equation. To solve this, the eddy viscosity is modeled similarly as in the smagorinsky case but with a subgrid scale turbulent kinetic energy which is solved with another transport equation. Something like nu(sgs)=C(nu)sqrt(K(sgs))*filterwidth. Just look at eugenes thesis